Abstract:Given the nonlinear and complex nature of atmospheric system combined with the uncertainties associated with initial conditions and models, it is not only a requirement from science but also a necessity to better serve user community to transit weather prediction from deterministic to probabilistic format. However, the reason behind the transition is not clear but full of debate and confusion to many including public, end users and even meteorologists themselves. To clarify some of these and to expedite the transition, a few issues were discussed. The ensemble forecasting which is a central technique to facilitate such a transition has been discussed in the companion paper of this article. In this paper, a few other issues related to ensemble based probabilistic forecasts were discussed, which include (1) how to measure the merits of a probabilistic forecast? (2) how to use probabilistic information in decision making process? and (3) why an ensemble based probabilistic forecast has, in general, more utility or economical value than a single value deterministic forecast does? To be easily understood and applicable to real world situations by readers especially forecasters and end users, plain language illustrated with examples was used to explain the related concepts.